Sp. Pl. 2: 1066. 1753
Leaves pinnate-pinnatifid; petioles ca. 1/3 length of blades, winged, with light brown hairs, becoming glabrate. Sterile leaves elliptic to oblong, ca. 0.5–1 m; pinnae broadly oblong, lacking persistent tuft of hairs at base; ultimate segments with base truncate, margins entire, apex rounded. Fertile leaves with greatly reduced, sporangia-bearing medial pinnae that wither early, giving appearance of no middle pinnae (hence the vernacular name, interrupted fern). Sporangia greenish, turning dark brown. 2n =44.
Phenology: Sporulation early spring–midsummer.
Habitat: 0–2300 m
St. Pierre and Miquelon, Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Conn., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis., Asia
Osmunda claytoniana is sparingly cultivated as an ornamental.